Headlight



c. K. RlzR HEADLIGHT May 19, 1931.

Filed Oct, 31, 1930 0 m V ,m

A TTORNEYS.

at: May 19,1931

UNITED STATES PATENT OFFICE com 1:. mm, or new YORK, 11. xi

mnmen'r i Application and October 81, ioso. mm a. 4mm. v

M invention relates to improvements in hea 'ghts for automobilesor other vehicles, and constitutes a continuation in part of my pending ap lication Serial No. 338,135,

5 filed February i 1929.

' This invention is particularly directed to a headlight reflector which will concentrate the direct light rays in a region below the direct line of vision of the driver of an approaching vehicle, and .contemplates a re flector formed of conic curves in a definite relation to the light source to accomplish the desired result.

In addition to confining the direct rays to the stated region, my reflector will roduce a uniformly lighted area on the h1ghway immediately in front of the vehicle and extending a suflicient distance to permit safe A come apparent from the follow ng description, taken in connection with the accompan ing drawings,'wherein:-

1 1 is avertical sectional view through 26 a re ector embodying my invention, particularly showing. the distribution of the I li ht rays; 1

' ig. 2, a top p an view' Fig. 3, a rear view of Fig. 2;

' 80 Fi 4, a top plan view of a modified form cf-re ector; and

' Fi 5, a rear view of Fig.4. Re erring to the drawin and more particularl to Figs. 1, 2 and 3, R designates genera y a headlight reflector constructed maccordance with my invention and comrising' conic curves .so arranged and reated with respect tea light source 2' as to produce the esi'red distribution of light 40 rays emanatin therefrom. The reflector R may be forms of any'suitable material as I for example sheet metal the inner sur ace .of which is adapted to the application of a reflecting plating or coating.

The generation of my reflectin surface may be more readily'understood a reference to a regular system of axes X-X,

.'Y "Y,'.and- ZZ, passing through the light source 2 and having a common ori 'n O 15 0 coincident with the filament of said light F er objects and advantages will Ibesource. A parabolic are 3 is disposed in the lane X-Y having its vertex a forwardiy of the light source 2 and its latus rectum BD coincident 'with the transverse axis XX, thereby coinciding the focusof the parabolic are 3 and the originO.

Said parabolic are 3 is revolved about its latus rectum B1) in such a manner that its vertex a describes a hyperbolicspiral in the plane YZ, a portion of such spiral being shown from a to 'b in Fig. 1.

As the said are 3 rotates, it continuously increases in size, accom' anied by a corresponding increase in the coal len h, until at t 0 point I) on the spiral, the are as become the are 3' of Fig. 2 havlng a focal distance 0b, and the latus rectum has increased to the value EF alon th axis X-X. The 111- dius vector of t e h perbolic spiral and the focal distance of said are are equal and c0- incident throu bout the spiral portion ab.

It will readily be seen' that if this rotation is continued the latus rectum of the par-' abolic arc will increase'beyond a practical value, that is to say, the refiectorwill be- 7 come extremely wide. Therefore, some limiting value GB of the latus rectum may be a selected as a maximum width of the reflector,

said value occurring when the vertex (1 of the parabolic are 3 has been rotated to the pointA on the hyperbolic spiral.

To complete the reflectlng surface, the parabolic are 3 is further rotated about the axis X-X with the vertexof said arc con tinuing along the hyperbolic spiral from A to c, or until the are again intersects the plane XY, said parabolic are being designated 3" in Fig. 2. That is 'to say,. the arc 3 rotates through an angle of 360 degrees from a to .0 to complete the reflecting sur-, 9 face. During this latter rotation, themaximum width ofthe parabola. is maintained constant and e ual to GH. Therefore,although the radius vector of the hyperbolic spira is continuously increasing to a maximum at the point '0, the focal distance of the parabolic arc decreases and the focus thereof continuously moves away from the li ht source 2.

the form of Figs. 4- and 5, I have M shown a reflector designated R, wherein the focal distance of the arabolic are 3 and the radius vector of t e hyperbolic spiral a-b.A-c continuously increase together from a to 0, whereby the focus of said are is maintained coincident With the light source throughout the generation of the entire reflecting surface. The value GH of the latus rectum of the parabolic are 3 is again taken as the maximum width of the reflector, but the reflecting surface from A to .0 formed by the continued rotation of the inceasing are 3 about its latus rectum is limited by its intersection with vertically extending side portions 4.

Thus, the reflectors R and R are the same in vertical cross section, and the generation of their surfaces from a to A along the hyperbolic spiral is the same, wherebv both of the reflectors are provided with reflecting surface about the light source 2 formed by the rotation of the increasing parabolic are 3 about its latus rectum passed through the light source. Such surface will provide a concentration of light rays at 5 in Fig. 1, for illuminating the highway some distance ahead of the vehicle to which the reflector may be applied. In addition, the much larger extended and broader reflecting surface from A to 0 will produce a diflused illumination of the area immediately in front and below the reflector, as at 6.

The distribution of light rays in a horizontal direction will produce an evenly distributed area of concentrated rays in the region 5, due to the parallel reflection of the surface 6A of the reflector, and a widened area of diffused light 6 from the portion A0.

However, in the form of Figs. i and 5, the diffused lighting at 6 will also be in the form of parallel light due to the fact that the reflecting surface A0 is generated by a parabolic arc revolved about its latus rectum which passes through the light source.

The reflectors R or B may be mounted on a vehicle in any suitable manner. As

shown in Fig. 1, the longitudinal YY axis of the reflector is inclined at a slight angle to the horizontal, permitting a greater range of illumination. However, it will become evident that no direct rays of light from the source 2 will come within the vision of an'approaching driver, all harmful rays being cut off and deflected downward by the reflector portion A0. The reflector may be enclosed in a pivotally mounted casing, to permit adjustment of the inclination thereof.

Various changes and modifications are contemplated provided they fall'within scope o the following claims.

I claim:

1. A light reflector of the character specified having a reflecting surface generated by the rotation of a continuously increasing parabolic arc in such a manner that the vertex of said are describes a spiral.-- 1

2. A light reflector of the character specified having a reflecting surface generated by the rotation of a continuously increasing fled having a reflecting surface, a portidn of which is generated by the rotation of a continuous y increasing parabolic are about its latus rectum in such a manner that the vertex of said arc describes a spiral.

a. Alight reflector of the character specified having a reflecting surface, a portion of which is generated by the rotation of a continuously increasing parabolic are about its latus rectum passed through the light source, in such a manner that the vertex of said are describes a spiral.

5. A light reflector of the character specified having a reflecting surface generated by the rotation of a continuously increasing parabolic are through a complete revolution about its latus rectum in such a manner that the vertex of said are describes a spiral.

6. A light reflector of the character specified having a reflecting surface generated by the rotation of a continuously increasing parabolic are through a complete revolution about its latus rectum passed through the light source, in such a manner that the ver- 3 tea: of said arc describes a spiral.

In testlmony whereof ll a'flix my signature.

CONRAD til. 

